Systems and methods for removing body tissue

ABSTRACT

Devices and methods for removing body tissue involving the use of a brush member ( 12 ) having a plurality of bristle members defining a capacity for carrying body tissue. The brush member ( 12 ) is capable of being manipulated within said body to thereby receive body tissue within said brush member ( 12 ) such that said body tissue may be carried and thereafter removed from said body. Also provided are protective devices ( 90 ) dimensioned to be positioned near an entrance into the target site, the protective devices ( 90 ) for establishing a barrier between the brush member ( 12 ) and at least a portion of the body tissue adjacent to the entrance. The protective devices ( 16 ) may comprise one of a cannula assembly ( 14 ) and a retractor assembly.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of the filing date under 35 USC §120or 365(c) of PCT Application entitled “Systems and Methods for RemovingBody Tissue,” Application No. PCT/US02/28926, filed Sep. 11, 2002, theentire contents of which are hereby expressly incorporated by referenceinto this disclosure as if set forth fully herein.

BACKGROUND OF THE INVENTION

I. Field of the Invention

This invention relates to devices and methods for removing body tissue.More particularly, the present invention relates to devices and methodsfor removing body tissue involving the use of a brush or brush-likeelement capable of collecting, carrying, or otherwise receiving bodytissue for removal.

II. Discussion of the Prior Art

A large variety of pathologies affecting many different body tissuesindicate the use of tissue ablation (i.e., removal or destruction of atissue). Examples of such procedures include knee meniscectomy, kneesynovectomy, chondromalacia and tears, loose body debridement, lateralretinacular release, plica removal, ligament and tendon release,contouring and sculpting of articular surfaces, debridement of inflamedsynovial tissue, capsulectomy in the knee, complete or partial resectionof internal organs, tumors and lesions.

Tissue ablation can be accomplished using many different ways, the twomain categories consisting of mechanical and energy focusing means.Mechanical tools are used to cut away the targeted tissue. Thermalenergy has also been used which heats the targeted tissue until thecells die. Lasers, radiofrequency waves, microwaves, ultrasound, andcryotherapy have all been used in thermal techniques. In a relatedtechnique, an electrical current is used to excite a fluid, creating aplasma layer. The highly energized plasma layer then incrementallydisintegrates layers of the tissue.

The existing techniques suffer from a host of disadvantages. Typically,mechanical devices are small and remove tissue in very small increments.As a result, when large amounts of tissue must be removed the excisiontime may be exorbitant. The energy focusing techniques, in addition tosuffering from the time disadvantage of the mechanical devices, arefurther limited. The energy levels applied to the tissue must beconservatively regulated to avoid damaging tissue beyond the targetedtissue.

One procedure, in particular, that is hindered by the existing devicesand techniques is a spinal discectomy (i.e., removal of intervertebraldisc material). Each disk is composed of an annulus fibrosus, a nucleuspulposus, and a pair of end caps which couple the annulus fibrosus andnucleus pulposus. The annulus fibrosus is an annular multi-layeredcomposite structure. Each layer is constructed of fibrous tissue andfibrocartilage with the fibers of each layer ordered and orientedgenerally in the same direction. The fibers of adjacent layers pass inopposite directions so that when the layers are combined they create amesh of concentric rings. The central cavity of the annulus houses thenucleus pulposus, which is a semi-gelatinous, highly elastic material.The final components are end caps constructed of thin layers of hyalinecartilage that cover both the top and bottom of each spinal disk. Theend caps cover both the annulus fibrosus and the nucleus pulposus andassure that the nucleus pulposus remains within the confines of theannulus fibrosus.

Oftentimes, disks become herniated, or bulge, due to structural damageto the annulus fibrosus. The bulging disk may place pressure on nearbynerves, which can lead to debilitating pain, numbness or muscleweakness. Treatments used to reduce the affects of a damaged disk rangefrom bed rest to spinal fusion. Due to the major shortcomings of thoseextreme treatments they are often not desirable. A discectomy, eitherfull or partial, can help to balance the burdens and benefits of bedrest and fusion or help prepare the intervertebral site for procedureslike fusion.

When a partial discectomy is performed, a portion of the nucleuspulposus of a herniated disc is excised. Partially removing the nucleusmaterial can reduce the pressure exerted by the nucleus on the annulusand reduce the bulging. In this procedure, the surgeon must first makean appropriate incision through the skin and other tissue layers, andthen typically create an access hole through the herniated annulus(i.e., an annulotomy) to treat the offending tissue. Such access holesare created with a variety of surgical instruments including scalpels,probes, trephines, etc., and the access hole may range in size from 3 to6 mm in diameter.

Upon entry into the interior annular space, the surgeon removes theoffending tissue. The tools typically used are only able to remove smallportions of tissue with each approach. As a result, removal of thetissue during a discectomy can take an exorbitant amount of time. Inaddition, in some cases, when ablation of the verterbral body surfacesadjacent to the disc is required, an additional tool must be used addingadditional time and steps to the procedure. The additional timerequirement of this procedure gives rise to a need for tools and methodsfor performing rapid discectomy and end plate ablation.

The present invention is directed at addressing this need andeliminating, or at least reducing, the effects of the shortcomings ofthe prior art systems as described above.

SUMMARY OF THE INVENTION

The present invention overcomes the drawbacks of the prior art byproviding, according to a first broad aspect of the present invention, adevice for removing body tissue comprising a brush member dimensionedfor introduction into a body. The brush member has a plurality ofbristle members defining a capacity for carrying body tissue. The brushmember is capable of being manipulated within the body to therebyreceive body tissue within the brush member such that the body tissuemay be carried and thereafter removed from the body.

In a further aspect of this device, the capacity for carrying bodytissue is defined by at least one of the space between the bristlemembers and the space between groupings of the bristle members. Thebristle members may be grouped to define at least one generally helicalspace for receiving and carrying body tissue therein, at least onegenerally axial space for receiving and carrying body tissue therein,and/or at least one generally arcuate space for receiving and carryingbody tissue therein.

In another aspect, the bristle members may be disposed in a generallysolid configuration with spacing sufficient to receive and carry bodytissue between said bristle members. In a further aspect, the brushmember has at least one of a generally cylindrical, generallyelliptical, and generally polygonal cross-sectional shape. The bristlemembers may comprise one of metal and plastic and, more particularly, atleast one of stainless steel wire, carbon-tempered steel wire,non-ferrous wire, and synthetic wire. The bristle members may begenerally cylindrical in cross-section with a diameter from 0.002 to0.100 inches.

According to certain aspects, the brush member may be generallycylindrical with a diameter from 0.082 to 1.225 inches. The brush membermay also include a stem member extending therefrom for use inmanipulating the brush member within said body. In a further aspect, thestem member may be generally cylindrical with a diameter from 0.125 to0.250 inches. The stem member may also be equipped with a quick-connectcoupling for engaging with at least one of a handle member and anextension member. In a further aspect, at least a portion of the bristlemembers may be retractable within the stem member. The stem member mayhave a length of from 1 to 24 inches and may include depth indicia.

Among the host of possible applications, the brush member may, accordingto a further broad aspect, be dimensioned to be introduced into anintervertebral space to receive, carry, and remove intervertebral discmaterial. In particular, the brush member may be used to removeintervertebral disc material in order to thereafter introduce a spinalimplant into the intervertebral space. In another related aspect, thebrush member may be dimensioned to be introduced into a vertebral bodyto receive, carry, and remove osseous material.

The present invention overcomes the drawbacks of the prior art byproviding, according to a second broad aspect of the present invention,a system for removing body tissue comprising a brush member of the typedescribed above in combination with a protector dimensioned to bepositioned near an entrance into a target site. The protectorestablishes a barrier between the brush member and at least a portion ofthe body tissue adjacent to the entrance. The brush member and protectormay be employed to remove body tissue during at least one of apercutaneous surgical procedure and an open surgical procedure.

In one further aspect, the protector comprises a cannula dimensioned toextend to the entrance of the target site, wherein the cannula has aninner lumen dimensioned to slideably receive the brush member forpassage into the target site. The cannula may include a handle memberfor directing the cannula to the entrance of the target site. In oneaspect, the inner lumen of the cannula and the brush member haveapproximately the same cross-sectional shape According to a furtherembodiment, the brush member includes a stem member, and the systemfurther includes a drive assembly capable of engaging with the stemmember for manipulating the brush member within the target site. Thedrive assembly may comprise one of a powered drive assembly coupled tothe stem member and a manual drive assembly coupled to the stem member.The powered drive assembly may comprise a power drill. The manual driveassembly may include a handle member capable of being coupled to thestem member and, in a further embodiment, may include an extensionmember coupled to the handle and a quick-connect coupling assembly forreleasable connection to the stem member In either case (powered ormanual), the drive assembly may include a stop member coupled to thestem member for controlling the depth to which the brush member can beadvanced into the target site.

According to one aspect of the system, the body tissue adjacent to theentrance may include at least one of neural tissue, dura tissue, andvasculature adjacent to the spine. If so, the cannula may include a lipmember at a distal end thereof dimensioned to retract at least one ofthe neural tissue, dura tissue, and vasculature.

In yet another aspect of the system of the present invention, theprotector comprises a retractor having at least one blade member forestablishing a barrier between the brush member and the body tissueadjacent to the entrance to the target site. The body tissue adjacent tothe entrance may include at least one of neural tissue and dura tissueof the spine. If so, the retractor may includes a first blade member forretracting the neural tissue and a second blade member for retractingthe dura tissue. The first blade member and second blade member may havea fixed or variable angle therebetween. In the latter case, theretractor may include a handle assembly for varying the angle betweenthe first blade member and the second blade member.

Among the host of applications of the system of the present invention,the brush member may, according to a further broad aspect, bedimensioned to be introduced into the intervertebral space to receive,carry, and remove intervertebral disc material. In particular, the brushmember may be used to remove intervertebral disc material in order tothereafter introduce a spinal implant into the intervertebral space. Inanother related aspect, the brush member may be dimensioned to beintroduced into a vertebral body to receive, carry, and remove osseousmaterial.

The present invention overcomes the drawbacks of the prior art byproviding, according to a third broad aspect of the present invention, amethod for removing body tissue, comprising the steps of: (a) creating aworking channel from a patient's skin to a surgical target site (viapercutaneous and/or open techniques); (b) inserting a brush member ofthe type set forth above into the surgical target site, the brush memberhaving a plurality of bristle members defining a capacity for carryingbody tissue; (c) manipulating the brush member within the body toreceive body tissue within the brush member; and (d) removing the brushmember from the surgical target site.

According to various aspects, the surgical target site may be anintervertebral disc space, and the step of inserting a brush member mayinclude, prior to the step of inserting the brush member, positioning aprotector near an entrance into the intervertebral disc space forestablishing a barrier between the brush member and at least one ofneural tissue, dura tissue, and vasculature adjacent to the entrance.The protector may comprise a cannula of the type described above and/orretractor (fixed or variable angle) of the type described above.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and advantages of the invention will become apparent uponreading the following detailed description and upon reference to thedrawings in which:

FIG. 1 is a perspective view of a system for removing body tissueaccording to one broad aspect of the present invention;

FIG. 2 is a side view of a cannula assembly forming part of the systemfor removing body tissue shown in FIG. 1;

FIGS. 3 and 4 are side and end views, respectively, of a brush memberand adapter member forming part of the tissue removal system of FIG. 1;

FIG. 5 is a side view of an extension member forming part of the tissueremoval system shown in FIG. 1;

FIGS. 6 and 7 are perspective and cross-sectional views, respectively,of a stopper assembly forming part of the tissue removal system shown inFIG. 1;

FIGS. 8 and 9 are side and top views, respectively, of the tissueremoval system of FIG. 1 in use performing a discectomy;

FIGS. 10 and 11 are perspective and side views, respectively, of aretractor forming an alternate aspect of the tissue removal system shownin FIG. 1 (without the cannula assembly 14);

FIG. 12 is a perspective view of a fixed angle tissue retractoraccording to one embodiment of the present invention;

FIG. 13 is a perspective view of a variable angle tissue retractoraccording to further embodiment of the present invention;

FIGS. 14 and 15 are top views showing the variable angle tissueretractor of FIG. 13 with the blade members generally closed (FIG. 14)and generally open (FIG. 15);

FIGS. 16 and 17 are top views of trays forming a kit according to oneembodiment of the present invention;

FIGS. 18-23 are side views showing various alternate configurations ofthe brush member according to the present invention;

FIG. 24 are cross-sectional views illustrating several manners ofproviding the brush member;

FIG. 25 is a top view of an alternate brush member configuration,disposed long a curved stem member; and

FIG. 26 is a top view of an alternate embodiment having multiple brushmembers and multiple stem members.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Illustrative embodiments of the invention are described below. In theinterest of clarity, not all features of an actual implementation aredescribed in this specification. It will of course be appreciated thatin the development of any such actual embodiment, numerousimplementation-specific decisions must be made to achieve thedevelopers' specific goals, such as compliance with system-related andbusiness-related constraints, which will vary from one implementation toanother. Moreover, it will be appreciated that such a development effortmight be complex and time-consuming, but would nevertheless be a routineundertaking for those of ordinary skill in the art having the benefit ofthis disclosure. The systems disclosed herein boast a variety ofinventive features and components that warrant patent protection, bothindividually and in combination.

The present invention overcomes the shortcomings of tissue ablationtechniques of the prior art by employing a brush member having aplurality of bristle members defining a capacity for carrying bodytissue. The capacity for carrying body tissue is based on the spacingbetween the individual bristle members and/or the spacing between one ormore groups of bristle members. While the present invention is describedbelow within the context of removing body tissue relating to the spine(i.e. intervertebral disc material and/or osseous material), it is to bereadily appreciated that the present invention may be used in any numberof different medical procedures. These may include, but are notnecessarily limited to, knee meniscectomy, knee synovectomy,chondromalacia and tears, loose body debridement, lateral retinacularrelease, plica removal, ligament and tendon release, contouring andsculpting of articular surfaces, debridement of inflamed synovialtissue, capsulectomy in the knee, complete or partial resection ofinternal organs, tumors and lesions. As used herein, the term “bodytissue” includes any tissue present in a living or dead body, includingbut not limited to tissue involved in the aforementioned list of medicalprocedures (including intervertebral disc material, cancellous andcortical bone, and fatty tissues).

FIG. 1 illustrates a system 10 for removing body tissue according to afirst broad aspect of the present invention. The system 10 includes abrush member 12 and a cannula assembly 14. Although describedimmediately below within the context of use with the cannula assembly14, it is to be understood at the outset that the brush member 12(including all the variations shown and described herein—and theirequivalents) forms an independently patentable aspect of the presentinvention. As will be described in greater particularity below, this isbased on the primary feature of providing the brush member 12 having aplurality of bristle members defining a capacity for carrying bodytissue, wherein the brush member 12 is capable of being manipulatedwithin the body to thereby receive body tissue within the brush member12 such that the body tissue may be carried and thereafter removed fromthe body. The capacity for carrying body tissue is defined by at leastone of the space between the individual bristle members forming thebrush member 12 and the space between groupings of bristle membersforming the brush member 12.

With combined reference to FIGS. 1-2, the cannula assembly 14 includes acannula member 16 and a handle member 18. The cannula member 16 has aninner lumen 20 dimensioned to pass the brush member 12 therethrough enroute to a surgical target site within a body. In one aspect of thepresent invention, the surgical target site may be one of theintervertebral disc space and an intravertebral body space. Importantly,the distal end of the cannula member 16 (opposite the handle member 18)serves to form a protective barrier between the brush member 12 andtissues adjacent to the surgical target site. Within the context ofspinal applications, such tissues may include, but are not necessarilylimited to, neural structures (i.e. exiting nerve roots) and dura tissue(during posterior and/or postero-lateral access to the spine) andvasculature (during anterior access to the spine). To further protectagainst inadvertent contact with such adjacent tissues (includingpinching such structures), the cannula assembly 14 is equipped a lipmember 22 capable of preventing such tissues from migrating into thedistal opening of the cannula 16.

With reference to FIGS. 1 and 3-4, the brush member 12 is provided, byway of example only, having its bristles disposed in a dual spiral orhelical grouping 24 along a stem member 26. This helical configuration24 of the bristles creates a generally helical space 28 extending alongthe length (L_(B)) of the brush member 12. This helical space 28, alongwith the space between the individual bristles forming the helicalgrouping 24, defines a carrying capacity within the brush member 12 forthe removal of body tissue. In a preferred embodiment, the length(L_(B)) of the brush member 12 may range from 0.25 to 4.0 inches and thediameter (D_(B)) of the brush member 12 may range from 0.082 to 1.225inches.

The bristles may be constructed from a number of materials that havesufficient strength to avoid shedding or dislodging of the bristles fromthe stem 26 during use and of proven safety in medical applications.Such bristle materials may include, by way of example, metal and plasticand, more particularly, stainless steel wire, carbon-tempered steelwire, non-ferrous wire, and synthetic materials (such as nylon or otherplastics). In a preferred embodiment, the individual bristles aregenerally cylindrical, each having a diameter ranging from 0.002 to0.100 inches. Although not shown, the bristles may also be providedhaving a square or other polygonal cross-section (depending on themethod of manufacture - which may include drawing, extrusion or molding)without departing from the scope of the present invention.

The stem member 26 is a generally rigid member that extends, accordingto one embodiment, away from the brush member 12 for connection to aquick-connect adapter 30. The stem member 26 may be provided having adiameter (D_(S)) ranging from 0.125 to 0.250 inches and a length rangingfrom 1 to 24 inches. The quick-connect adapter 30 enables the stemmember 26 to be quickly coupled or de-coupled from a manual driveassembly 32 to be described below. The quick connect adapter 30 isgenerally cylindrical with a connector portion 34 on its proximal end.The distal end of the quick connect adapter 30 may be coupled to thestem member 26 by crimping or by any mechanical connection that providessufficient strength to withstand torsional forces during rotation of thebrush member 12. The male connector portion 34 includes a flat surface34 that provides a bearing surface that transmits rotation between thebrush member 12 and the manual drive assembly 32, and a concentricchannel 53 that is engaged by a retractable feature in a mating devicethat prevents axial movement between the quick connect adapter 30 andthe a mating device. It should be appreciated that there are many knownconnection mechanisms that may be substituted without departing from thescope of the present invention, including but not limited to a Jacob'sadapter.

Turning to FIGS. 1 and 5, the manual drive assembly 32 includes, by wayof example, an extension adapter 40 having a female quick-connect collet42 at its distal end and a male connecting portion 44 at its proximalend. The female quick connect collet 42 is of known construction andfunctions to couple the extension adapter 40 to the quick-connectadapter 30. The male connecting portion 44 is of similar construction tothe corresponding connecting portion 34 of the quick connect adapter 30and, as such, need not be described again here, except to point out thatthe connecting portion 44 of the extension adapter 40 is, in a preferredembodiment, to be coupled to a manual handle (not shown) such that asurgeon may impart rotational force on the brush member 12 to effectuatethe tissue removal of the present invention. According to an alternateembodiment, the connecting portion 44 may be coupled to a power drill(thus forming a powered drive mechanism according to the presentinvention).

The extension adapter 40 may be provided with certain depth managementfeatures to control or manage the extent to which the brush member 12 isintroduced into the target surgical site. In one embodiment, these depthmanagement features may include indicia 46 disposed along the length ofthe extension adapter 40 (denoting, by way of example, a depth rangingfrom 0 to 50 mm) and a plurality of notches 48. These depth managementfeatures are particularly suited for use with a stopper assembly 50shown generally in FIG. 1 and in detail in FIGS. 6-7.

The stopper assembly 50 includes a stop member 52, a detent member 54, aspring 56, and a locking pin 58. The stop member 52 includes an aperture60 dimensioned to receive the extension member 40, as well as a sideaperture 62 for receiving the detent member 54. The detent member 54includes a locking pin slot 64, an engagement aperture 66, and anextension 68. The slot 64 allows the locking pin 58 to travel therein tocontrol the inward and outward travel of the detent member 54 within thestop member 52. The aperture 66 includes an enlarged region 70 and anengagement ridge 72 (hence the “semi-constrained” terminology). When thedetent 54 is pushed into the stop member 52 (by urging against thespring 56), the enlarged region 70 is moved into general coaxialalignment with the aperture 60 such that the extension adapter 40 may bepassed through the stop member 52. Once positioned at a desired locationalong the notched region 48 of the extension adapter 40, the detentmember 54 may be released such that the engagement ridge 72 will bedisposed within one of the notches 48 and thereby restrict the movementof the extension adapter 40 relative to the stop member 52. In apreferred embodiment, the stop member 52 does not restrict eitherrotation of the brush member 12 or translation in the proximaldirection. As a result, the brush member 12 is limited to a depth thatcan be predetermined while still allowing rotation and limited back andforth motion.

With reference to FIGS. 8-9, the tissue removal system 10 will now bedescribed, by way of example only, in use within in the context of adiscectomy procedure despite its general utility in any of a variety oftissue removal procedures. First, a working channel is formed betweenthe patient's skin and the surgical target site, which in this case isan intervertebral disc space. The working channel be created via atraditional “open” techniques or a percutaneous or “minimal access”technique. With the working channel created, the cannula 16 may beinserted such that its distal end (with the lip member 22) is disposedadjacent to or in the generally proximity of the annulus. In a preferredembodiment, the lip member 22 may be used to prevent any surroundingtissue (such as exiting nerve roots and/or dura tissue in the case ofthe posterolateral approach shown best in FIG. 9) from migrating intothe distal opening of the cannula 16. An annulotomy device of knownconstruction may be extended to the disc through the cannula 16 toremove a section of the disc annulus.

Thereafter, the discectomy brush 12 may be extended into the discnucleus via the cannula 16 and disc annulus. The brush member 12 maythen be rotated, manually or by power means such as a drill, to removedisc material. Depending on the diameter of the brush member 12 and thedistance between the adjacent vertebrae, the discectomy brush 12 may beused to remove tissue as well as ablate or partially decorticate thesurfaces of the adjacent vertebrae. The brush member 12 may then beremoved and may be discarded or cleaned depending on the brush material.In one embodiment, the brush is comprised of plastic and another ofstainless steel.

After removal of such disc material and, optionally, preparation of thevertebral endplates, any of a variety of spinal implants may be insertedinto the space created by the discectomy brush. These spinal implantsmay include, but are not necessarily limited to, allograft products,ceramic spacers, and total disc replacement devices. Whatever theimplant, it should ideally be inserted into this space via the cannula16. The annulus opening may then be closed (through any known means,such as sutures or patch devices or sealing compounds) and then thecannula 16 removed. It should be readily understood that anterior,extreme lateral, posterolateral or posterior approaches may be utilizedusing the principles of the present invention.

FIGS. 10-11 illustrate another broad aspect of the present invention,wherein a retractor 80 is provided (as opposed to the cannula assembly16 described above) for the purpose of establishing a protective barrierbetween the brush member 12 and the tissues adjacent to the surgicaltarget site (again, the intervertebral disc space). To accomplish this,the retractor 80 provides a pair of retractor blade 82, 84, whichcollectively form a generally “V” shaped construct capable of preventingthe exiting nerve root (via blade 82) and the dura tissue (via blade 84)from migrating into a region that might otherwise result in the unwantedcontact between the brush member 12 and these tissues. To facilitatethis, each blade member 82, 84 is preferably equipped with a lip member83 similar to lip member 22 of the cannula 16. As shown in FIG. 12,these blade members 82, 84 may be positioned relative to the surgicaltarget site by virtue of an elongate curved shaft 86 coupled to a handlemember 88. In one embodiment, the blade members 82, 84 have a fixedangle relative to one another ranging from between 50 and 75 degrees.

In an alternate embodiment shown in FIGS. 13-15, the retractor 80 mayhave blade members 82, 84 that are variable angle relative to oneanother. To accomplish this, a handle assembly 90 is provided having apair of gripping elements 92, 94 which, upon manipulation towards (FIG.14) and away (FIG. 15) from one another serve to increase and decrease,respectively, the angle between the blade members 82, 84. A shaft 85extends between the gripping elements 92, 94 for independently couplingthe blade members 82, 84 to one of the gripping elements 92, 94. Alocking feature may be optionally be provided by equipping the firstgripping element 92 with an arcuate, ribbed engagement element 96 whichcooperates with a trigger member 98 coupled to the second grippingelement 94. A spring 100 is disposed between the gripping elements 92,94 and over a portion of the engagement element 96 to aid in the lockingand unlocking of the handle assembly 90. In one embodiment, the anglebetween the blade members 82, 84 may be varied between 0 and 180 degreesand, more preferably, 0 to 90 degrees. The ability to close the anglebetween the blades 82, 84 (that is, to an angle of approximately 0 to 30degrees) is helpful in that it may aid in placing the blades 82, 84 inproper position to form the barrier between the surrounding tissue andthe brush member 12, such as by being introduced in the closed orreduced angle and thereafter opening the blades 82, 84 to thereby moregently move the adjacent structures aside.

With reference to FIGS. 16-17, the tissue removal system 10 of thepresent invention may be provided in any number of suitable fashions,including the kit fashion shown comprising a first tray 110 and a secondtray 112. By way of example only, the tray 110 may be provided having aplurality of brush members 12 of varying size and length to accommodatethe particular surgical need or procedure. Tray 110 may also includecomponents of the given drive mechanism, such as a pair of extensionmembers 40 (for coupling to the quick coupling adapters 30 attached tothe brush members 12), a pair of stopper assemblies 50, a handleassembly 51 (for quick-connect coupling to the extension member 40), anda pair of retractors 80 (in this embodiment, the fixed angleconfiguration). Tray 112 may include a plurality of cannula assemblies14 having cannulas 16 with inner lumens having the same or similardiameters as the brush members 12 contained in tray 110. Providing thetissue removal system 10 of the present invention in this fashion isconvenient and offers significant time savings and flexibility intailoring the system 10 depending upon the given surgical procedures.

As mentioned above, the brush member 12 forms an independent andsignificant feature of the present invention based on its capacity tocarry body tissue both within the bristles of the brush, as well asbetween the groupings of bristles. Although shown above with referenceto a dual spiral configuration, it is to be readily appreciated that thebrush member 12 may be provided in any number of suitable fashionswithout departing from the scope of the present invention. For example,the brush member 12 may be provided having a single spiral bristlegrouping 24 (see FIG. 18) defining a generally helical space 28 forreceiving and carrying body tissue, a generally solid configuration (seeFIG. 19) wherein the bristles have sufficient spacing therebetween toreceive and carry body tissue, one or more radially extending bristlegroupings 24 (FIGS. 20-21) defining at least one generally arcuate space28 for receiving and carrying body tissue, and one or more axiallydisposed bristle groupings 24 (FIGS. 22-23) defining at least onegenerally axial space 28 for receiving and carrying body tissue.Moreover, the cross-sectional shape of the brush member 12 may vary fromthe generally circular cross-section of the cylindrical brush member 12shown above, to any of a variety of polygonal cross-sections, includingbut not limited to those shown in FIG. 24.

In a further aspect of the present invention, it is contemplated thatthe bristles forming the brush member 12 may be retractable toward thestem member 26 allowing for the brush diameter to be increased afterinsertion into the material to be excised. That feature may beaccomplished by construction of the brush portion 11 from a materialsuch as Nitinol or other “memory metal” or through a mechanical orelectro-mechanical mechanism. It is similarly contemplated to (as shownin FIG. 25) provide the brush member 12 formed along a curved (orpossibly rounded) stem member 26 for manual or automated manipulationwithin the target site (such as back-and-forth and/or side-to-side), aswell as (as shown in FIG. 26) provide a plurality of brush members 12,each having a stem member 26 capable of independent manipulation (suchas via rotation) and/or unison operation (moving the entireconfiguration back-and-forth and/or side-to-side) to effectuate bodytissue removal.

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof have been shown by wayof example in the drawings and are herein described in detail. It shouldbe understood, however, that the description herein of specificembodiments is not intended to limit the invention to the particularforms disclosed, but on the contrary, the invention is to cover allmodifications, equivalents, and alternatives falling within the spiritand scope of the invention as defined by the appended claims.

1. A method for removing intervertebral disc material, comprising thesteps of: creating a working channel from a patient's skin to anintervertebral disc space; providing a protector, said protector havinga longitudinal axis and including retractor having first and secondgenerally rectangular, planar blade members fixed in position relativeto one another to form a generally V-shaped construct for establishing abarrier, said construct having a longitudinal axis extending in agenerally parallel orientation relative to said longitudinal axis ofsaid protector; positioning said protector near an entrance into saidintervertebral disc space between said working channel and at least twoof neural tissue, dura tissue, and vasculature adjacent to said entrancesuch that said first blade member prevents neural tissue from migratinginto said working channel, and said second blade member prevents atleast one of dura tissue and vasculature from migrating into saidchannel; inserting a brush member through the working channel into saidintervertebral disc space, said brush member having a length rangingfrom 0.25 to 4.0 inches, a diameter ranging from 0.082 to 1.225 inches,and a plurality of bristle members disposed in a helical configurationdefining a capacity for carrying intervertebral disc material whereinsaid protector prevents contact between said brush member, said neuraltissue and said at least one of dura tissue and vasculature;manipulating said brush member within said intervertebral disc space toreceive intervertebral disc material within said brush member; andremoving said brush member from said intervertebral disc space.
 2. Themethod of claim 1, wherein said step of creating a working channel tothe intervertebral disc space is accomplished via at least one ofpercutaneous surgical procedure and an open surgical procedure.
 3. Themethod of claim 1, wherein said protector further comprises a cannuladimensioned to extend to said entrance of said intervertebral discspace, said cannula having an inner lumen dimensioned to slideablyreceive said brush member for passage into said intervertebral discspace.
 4. The method of claim 3, wherein said cannula includes a lipmember at a distal end thereof dimensioned to retract at least one ofsaid neural tissue, dura tissue, and vasculature adjacent to said spine.5. The method of claim 3, wherein said inner lumen of said cannula andsaid brush member have approximately the same cross-sectional shape. 6.The method of claim 1, wherein said brush member includes a stem member,and further including the step of providing a drive assembly capable ofengaging with said stem member for manipulating said brush member withinsaid intervertebral disc space.
 7. The method of claim 6, wherein saiddrive assembly comprises one of a powered drive assembly coupled to saidstem member and a manual drive assembly coupled to said stem member. 8.The method of claim 7, wherein said powered drive assembly is a powerdrill.
 9. The method of claim 7, wherein said manual drive assemblyincludes a handle member capable of being coupled to said stem member.10. The method of claim 9, wherein said manual drive assembly includesan extension member coupled to said handle and a quick-connect couplingassembly for releasable connection to said stem member.
 11. The methodof claim 7, wherein said drive assembly includes a stop member coupledto said stem member for controlling the depth to which said brush membercan be advanced into said intervertebral disc space.